Lichess


Lichess is a free and open-source Internet chess server run by a non-profit organization of the same name. Anyone can play anonymously, although players may register an account on the site to play rated games. Lichess is ad-free and all the features are available for free, as the site is funded by donations from patrons.

History

Lichess was founded in 2010 by French programmer Thibault Duplessis. The software running Lichess and the design are open source under the AGPL license.
On February 11, 2015, an official Lichess mobile app was released for Android devices. An app for mobile devices running iOS was released on March 4, 2015.
As of July 12, 2020, lichess.org had a global rank of 1,138 at Alexa, with most of its visitors coming from the United States, India, and Spain. According to the Alexa rank, Lichess is ranked second only to Chess.com as one of the most popular internet chess servers in the world.
Being ad-free, Lichess relies on donated money to maintain over a dozen servers with over a hundred processor cores while paying programmers.

Features

The website allows users to play games of live and correspondence chess against other players at different time controls. It has training features, including chess basics, tactics training, chess coordinates, a chess video library, an opening explorer, studies, and an analysis board. It also has a section where chess coaches can advertise their services to users.
In addition to enabling blindfold chess, the website supports the following chess variants:
Lichess was the first chess-site to have features to help visually impaired people play chess on a website. It also has a chess puzzle-based CAPTCHA system.
Users can also play games against the Stockfish chess engine at a number of difficulty levels. They may also analyze specific positions from standard chess or any of the supported chess variants. The website implements a version of the Stockfish engine that runs on the user's local machine within the user's web browser for limited or infinite analysis, which will calculate best lines of play or major opponent threats. An opening book based on games played on the site or a database of two million games played by FIDE titled players is available. In the Antichess analysis board, users can utilize Mark Watkins's antichess solution database.
For registered players, Lichess employs a Glicko-2 rating system, and grants the ability to compete in tournaments, post in the forums, and request a server-side full game analysis for any finalized game. The ratings for standard chess are categorized into Ultrabullet, Bullet, Blitz, Rapid, or Classical, depending on the game's total time or estimated total time.
A Lichess mobile app is available for iOS and Android.
In December 2017 Lichess began hosting a monthly Lichess Titled Arena for titled players featuring some of the best players in the world playing bullet chess. Magnus Carlsen won the first titled arena.